Synthesis Of Tri Research Articles

Synthesis of tri(m‐sulfonatedphenyl)phosphine (tppts): The importance of ph in the work‐up

Controlling the pH during workup allows synthesis of TPPTS. P(m-C6H4SO3Na)3, without interference from the oxide. The recrystallized yield is 70% based on P(m-C6H4SO3Na)3 3H2O from PPh3.

S-Acylthioethyl prodrugs of phosphonoformate

Due to its highly ionic nature, the antiviral phosphonoformate shows poor penetration into cells and here bioreversible prodrugs of phosphonoformate are designed in an attempt to improve its transport properties. The key step in the syntheses of tri[2-( S-acylthio)ethyl] esters of phosphonoformate 9 was the reaction between bis[2-( S-acylthio)ethyl] phosphite and 2-( S-acylthio)ethyl chloroformate in the presence of N,O-bis(trimethylsilyl)acetamide. The water soluble di[2-( S-acylthio)ethyl] esters 10 were prepared by reaction of the triesters 9 with sodium iodide. The diesters 10 showed comparable activity to phosphonoformate against herpes simplex virus-1 (HSV-1) in cell cultures, this result being consistent with their cleavage to phosphonoformate observed in rat tissue. However, phosphonoformate could not be detected in plasma following oral administration of the triesters 9 and diesters 10 to rats.

The first application of samarium(II) diiodide for the formation of Group 14 element catenates: synthesis of tri- or poly-germanes and polystannanes

Some Group 14 element catenates such as tri- or poly-germanes and polystannanes are synthesized by use of the one-electron reducing agent Sml2.

Two Enzyme Classes Active in Green Peach Aphid (Homoptera: Aphididae) Bioassays

Discovery of novel insecticidal gene products is essential for pest-control strategies using genetically modified plants. We used an empirical procedure to test filtrates from > 10,000 microbial fermentations to identify proteins active in bioassays on several target insects. Two proteins active in bioassays with green peach aphids, Myzus persicae (Sulzer), were discovered in microbial filtrates. These proteins were active in the bioassay because they modified the dietary sucrose. Consequently, the aphids were either unable to survive on or unwilling to feed on the sucrose-depleted diets. One of these proteins catalyzes the synthesis of tri- and tetra-saccharides from sucrose, indicating that this protein is in the hexosyl-transferase class of enzymes. The other microbial filtrate has invertase like activity. These two types of proteins are not viable candidates for insect control strategies because the modification of sucrose in the phloem of plants would have deleterious effects on the plant.

Synthesis of tri- and tetrapeptide S: the extended C-terminus of bleomycin A2

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTSynthesis of tri- and tetrapeptide S: the extended C-terminus of bleomycin A2Dale L. Boger and Royce F. MenezesCite this: J. Org. Chem. 1992, 57, 16, 4331–4333Publication Date (Print):July 1, 1992Publication History Published online1 May 2002Published inissue 1 July 1992https://doi.org/10.1021/jo00042a003RIGHTS & PERMISSIONSArticle Views508Altmetric-Citations24LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (406 KB) Get e-AlertsSupporting Info (1)»Supporting Information Supporting Information Get e-Alerts

Synthesis and Diels Alder reaction of 2,3-dihydro-2,3-dimethylene-1,4-benzodioxin.

2,3-dohydro-2,3-dimethylene-1,4-benzodioxin undergoes an easy Diels Alder cycloaddition with a variety of dienophiles. The new products obtained constitute attractive compounds as useful intermediates in the synthesis of tri and tetracyclic systems.

Sulfenylation of some pyrroles and indoles

AbstractMethylsulfenylation of 1‐substituted pyrroles and indoles was observed using 1‐(methylthio)morpholine and an acid catalyst or with methylsulfenyl chloride and excess pyridine. 1‐Substituents which are activating or weakly deactivating towards electrophilic substitution such as alkyl, 2‐cyanoethyl, dimethylamino, trialkylsilyl, 2‐chloroethyl and 2‐phenylsulfonylethyl were used. The 2‐chloroethyl and 2‐phenylsulfonylethyl groups which can be removed with a strong base can be used to obtain 1H‐methylthiopyrroles and indoles. 1‐Phenylsulfonyl and 1‐acetyl substituents are too strongly deactivating for these sulfenylations to be successful. Mono and disubstituted pyrroles and monosubstituted indoles can be isolated from these reactions, however, because the methylthio group is activating towards electrophilic substitution the main advantage of these reactions is the synthesis of tri and tetrasubstituted pyrroles and disubstituted indoles. 1‐Methyl‐2,3,4,5‐tetra‐methylthiopyrrole and 1‐methyl‐2,3‐dimethylthioindole are oxidized to the corresponding 3,4‐disulfoxide and 3‐sulfoxide and with excess oxidizing agent to the tetrasulfone and disulfone, respectively.

Zur Umsetzung von Tri(phenylethinyl)arsan und -stiban mit Octacarbonyldicobalt; Kristallstruktur von (Ph– C≡ C)As[(η2-C≡ C – Ph)Co2(CO)6]2 / Reaction of Tri(phenylethynyl)arsane and -stibane with Octacarbonyldicobalt; Crystal Structure of (Ph–C≡C)As[η2-C≡C–Ph)Co2(CO)6]2

The synthesis of tri(phenylethynyl)arsane (1) and -stibane (7) is discussed. Octacarbonyldicobalt reacts selectively with 1 or 7 to yield the η2-side-on co-ordinated phenylethynyl complexes (Ph–C=C)nE[(η2-C≡C–Ph)Co2(CO)6]3-n (E = As: n = 2: 3, n = 1: 4, n = 0: 5; E = Sb: n = 2: 8; n = 1: 9; n = 0: 10), which contain sterically hindered carbon-cobalt tetrahedrane cluster units. 3 gives upon heating {(Ph–C≡C)2As[(η2-C=C–Ph)Co2(CO)5]}2 (6) a compound containing a six-membered Co2As2C2 ring. All new compounds have been characterized by analytical and spectroscopic data (IR, 1H, 13C NMR), and (Ph –C≡C)As[(η2-C≡C–Ph)Co2(CO)6]2 (4) by X-ray analysis.

A-B-A Triblock and (A-B)nSegmented Block Copolymers of Styrene and Ethylene Oxide via Thermal Iniferters

Abstract A free radical technique is described for the synthesis of tri- and multiblock copolymers of styrene and ethylene oxide through polyethylene oxide-based thermal “iniferters.” The mono- or dihydroxy-terminated oligomeric polyethylene oxides were chemically transformed to the secondary amine terminated species. Thiocarba-mylation and oxidation of the amine groups gave rise to macro- or polymeric thiuram disulfides called macro- or polymeric “iniferters,” respectively. Thermal polymerization of styrene in the presence of the macro iniferter led to the formation of their perfect triblock copolymers, with styrene forming the central block. Utilization of the polymeric iniferter, on the other hand, give rise to (A-B)n type segmented copolymers containing as many as 3 (A-B) sequences. The length of each block could be regulated by the choice of the appropriate iniferter and its relative concentration with respect to the monomer. The iniferters and the block copolymers were characterized.

Chemistry of novel compounds with multifunctional carbon structure. Part 3. Synthesis of α-azido-α-fluoro-α-(phenylthio and ethylthio)acetates

The synthesis of tri- and tetra-functional carbon compounds which possess three or four different functional groups on the same carbon atom is described.Reactions of ethyl bromofluoro- or chlorofluoro-acetate (4b) or (5) with several heteroatomic nucleophiles give the corresponding α-functionalised α-fluoroacetates (6a–g) in good yields. The trifunctional carbon compounds which have phenylthio and ethylthio functionalities (6a,b) are brominated with NBS to afford the tetrafunctional carbon compounds, ethyl bromofluoro(phenylthio and ethylthio)acetates (8a,b). The bromo derivatives (8a,b) can be converted into another type of tetrafunctional carbon compound, ethyl azidofluoro(phenylthio and ethylthio)acetates (9a,b) by reaction with sodium azide under phase-transfer conditions. Ethyl azidobromofluoroacetate (12) is prepared from the dibromo derivative (4c) in a similar manner.The noticeable reactivities which are caused by the novel multifunctionalised carbon structures are also reported.

Functionalization of crown ethers: an approach to the enzyme model for peptide synthesis

Abstract

Synthesis of tri‐, tetra‐, and penta‐deuterated forms of vitamin a

AbstractThe synthesis of 20,20,20‐trideutero, 14,20,20,20‐tetradeutero, 12,14,20,20,20‐pentadeutero, and 10,19,19,19‐tetradeutero analogs of retinoic acid ethyl ester and retinyl acetate, by a modified Wittig‐Horner synthesis, is described. Deuterium was introduced by base‐catalyzed exchange into appropriate intermediates. The 10,19,19,19‐2H4‐vitamin A, because of its high isotopic integrity (>98% 2H4), is the preferred analog for biological studies of vitamin A metabolism.

Synthesis of nitro-substituted dioxotetrahydrodioxapyrenes and 6H-dibenzo[b,d]pyran-6-one

Methods for the synthesis of tri- and tetranitro-substituted 5,9-dioxo-4,5,9,10-tetrahydro-4,10-dioxapyrenes, 5,10-dioxo-4,5,9,10-tetrahydro-4,9-dioxapyrenes, and 6H-dibenzo[b,d]pyran-6-one were developed in a search for effective sensitizers for electrophotographic layers based on carbazole-containing polymers. The possibility of the production of nitro compounds that contain three vicinal nitro groups was demonstrated. Under severe nitration conditions 2,4,8-trinitro-6H-dibenzo[b,d]pyran-6-one is cleaved to give 2-hydroxy-2′-carboxy-3,5,4′-trinitro-biphenyl, which is resistant to cyclization to give the starting compound, evidently because of the existence of an intramolecular hydrogen bond between the hydroxy group and the nitro group.

Chemistry of .alpha.-silyl carbonyl compounds. 9. Synthesis of tri- and tetrasubstituted olefins from .alpha.-silyl esters

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTChemistry of .alpha.-silyl carbonyl compounds. 9. Synthesis of tri- and tetrasubstituted olefins from .alpha.-silyl estersDavid Hernandez and Gerald L. LarsonCite this: J. Org. Chem. 1984, 49, 22, 4285–4287Publication Date (Print):November 1, 1984Publication History Published online1 May 2002Published inissue 1 November 1984https://doi.org/10.1021/jo00196a033RIGHTS & PERMISSIONSArticle Views218Altmetric-Citations17LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (424 KB) Get e-Alerts Get e-Alerts

ChemInform Abstract: A NOVEL SYNTHESIS OF TRI‐, DI‐, AND MONO‐9‐ACRIDINYL DERIVATIVES OF TETRA‐, TRI‐, AND DIAMINES

Chemischer InformationsdienstVolume 14, Issue 26 Heterocyclic Compounds ChemInform Abstract: A NOVEL SYNTHESIS OF TRI-, DI-, AND MONO-9-ACRIDINYL DERIVATIVES OF TETRA-, TRI-, AND DIAMINES J. B. HANSEN, J. B. HANSENSearch for more papers by this authorO. BUCHARDT, O. BUCHARDTSearch for more papers by this author J. B. HANSEN, J. B. HANSENSearch for more papers by this authorO. BUCHARDT, O. BUCHARDTSearch for more papers by this author First published: June 28, 1983 https://doi.org/10.1002/chin.198326232Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat No abstract is available for this article. Volume14, Issue26June 28, 1983 RelatedInformation

Polyfuryl(aryl)alkanes and their derivatives. 1. Synthesis of tri- and tetrafurylmethanes

Derivatives of tri- and tetrafurylmethane were obtained by the reaction of alkylfurans with chloroform and carbon tetrachloride in benzene in the presence of catalytic amounts of 58% HClo4.

The synthesis of tri- and tetra-saccharide oxazolines

The synthesis of tri- and tetra-saccharide oxazolines

Syntheses of tri, penta and nonameric nucleotides containing purine and pteridine bases

Syntheses of tri, penta and nonameric nucleotides containing purine and pteridine bases

Synthesis of tri- O-methyl derivatives of D- glycero- L- manno-heptose

Synthesis of tri- O-methyl derivatives of D- glycero- L- manno-heptose

Two crystalline pentofuranosyl bromides: tri- O-( p-nitrobenzoyl)-β- D-ribofuranosyl bromide and tri- O-( p-nitrobenzoyl)-α,β- D-xylofuranosyl bromide

Methyl α,β- D-ribofuranoside was p-nitrobenzoylated to give methyl tri- O-( p-nitrobenzoyl)-β- D-ribofuranoside ( 2),and this was treated with HBr in acetic acid to give tri- O-( p-nitrobenzoyl)-β- D-ribofuranosyl bromide ( 3). Bromide 3 could be converted into 2,5-anhydro-3,4,6-tri- O-( p-nitrobenzoyl)- D-allononitrile ( 4) with Hg(CN) 2, or hydrolyzed to 2,3,5-tri- O-( p-nitrobenzoyl)- D-ribose ( 5). On p-nitro- benzoylation, 5 gave tetra- O-( p-nitrobenzoyl)-β- D-ribofuranose ( 6). The synthesis of tri- O-( p-nitrobenzoyl)-α-β- D-xylofuranosyl bromide ( 11) started with methyl 3,5- O-isopropylidene-β- D-xyldfuranoside ( 7), which was p-nitrobenzoylated to give ester 8; this was then hydrolyzed, and the product p-nitrobenzoylated to give methyl tri- O-( p-nitrobenzoyl)-β- D-xylofuranoside ( 10) which, on treatment with HBr in CH 2Cl 2, afforded the desired bromide ( 11). Nucleophilic replacement with Hg(CN) 2 afforded 2,5-anhydro-3,4,6-tri- O-( p-nitrobenzoyl)- D-gulononitrile ( 12).